We are requesting partial funding of an echoplanar gradient probe upgrade for the 1.5T whole body research scanner of the Johns Hopkins University School of Medicine. The major user group consists of five NIH-funded principal investigators and two non NIH-funded researchers all focusing on the investigation of myocardial function via measurement of finite strains using MRI tagging methods. Critical need for this equipment has increased because further results indicate significant data deterioration and ambiguity related to the limitations of current equipment, including: 1) the need to obtain ECG-gated images over 128 or more cardiac cycles, 2) the inability to freeze respiratory motion, and 3) the physiologic instability of the experimental preparation over the long (over 3 hours) experimental time required for the proposed experiments. Improvement in the temporal resolution of the experiments as well as the shortening of total experimental time has become critical to the successful completion of the projects of this major user group. A second group of three investigators, two of whom are NIH-funded, will share in the use of the instrument to obtain real-time evaluations of diffusion and perfusion within brain tumors and ischemic brain. This will help answer the following fundamental questions. (1) Are MRS measurements dependent upon physiologic parameters such as diffusion and blood flow in tumors? (2) In the context of cerebral ischemia, can these measurements differentiate different levels of ischemic injury? We are requesting this upgrade to our research scanner as we have no other alternative to address the critical scientific need of the research projects herein described.